Discussion Paper (continued)
Uncertainty about "climate sensitivity"—the impact on temperature of increased concentrations of greenhouse gases—grew from the IPCC's 4th to 5th Assessment Reports. The authors conclude that this "bad news" outweighs the "good news": a lower value for the bottom end of the range for temperature rise.
The authors argue that reducing uncertainty about the impacts of climate change will facilitate effective adaptation, even in the absence of effective international climate agreements.
"Internationally-Tradable Permits Can Be Riskier for a Country than an Internally-Imposed Carbon Price"
Uncertainty in the form of country-specific abatement-cost shocks, together with cross-border revenue flows from internationally-tradable permits, can lead to greater country risk from an international emissions-trading system than from the imposition of a uniform carbon price.
The authors examine the effect of real energy prices and a simulated carbon price on production and net imports. They find modest adverse competitiveness effects for energy-intensive industries.
The authors argue that the climate change global commons problem will be solved only through coherent carbon pricing. They discuss a roadmap for negotiating a uniform carbon price across countries, for verification of emissions reduction, and for a governance process to which countries would commit.
The authors explore several approaches to an ambitious climate agreement in Paris in late 2015—including through carbon pricing.
By Joseph E. Aldy, Faculty Affiliate, Harvard Project on Climate Agreements
Inadequate policy surveillance has undermined the effectiveness of multilateral climate agreements. To illustrate an alternative approach to transparency, the author evaluated policy surveillance under the 2009 G-20 fossil fuel subsidies agreement. The Leaders of the Group of 20 nations tasked their energy and finance ministers to identify and phase-out fossil fuel subsidies. The G-20 leaders agreed to submit their subsidy reform strategies to peer review and to independent expert review conducted by international organizations.
This paper posits the conceptually useful allegory of a futuristic "World Climate Assembly" that votes on global carbon emissions via the basic principle of majority rule. Two variants are considered. One is to vote on a universal price (or tax) that is internationally harmonized, but the proceeds from which are domestically retained. The other is to vote on the overall quantity of total worldwide emissions, which are then distributed for free (via a pre-decided fractional subdivision formula) as individual allowance permits that are subsequently marketed in an international cap-and-trade system.
The authors consider the role of integrated assessment models in estimating the social cost of carbon—an estimation that is important in the formulation of U.S. climate policy.
Carbon taxes, which postpone extraction of fossil fuels and reduce cumulative carbon emissions, also have economic advantages over taxes on capital.